Corrugated cardboard is extensively used as packing material in transport packages, consumer packages, and wrappings. Corrugated cardboard has at least one fluting paper, curved in the form of flutes, and at least one flat surface paper, that is, a liner. Often, one fluting paper is glued between two liners. There may also be several fluted layers in corrugated cardboard in order to improve strength and durability. Typically, starch size is used as the glue, but for humid conditions also wet-strength glue may be used.
It is important for the quality of corrugated cardboard that the gluing holds and the surfaces of the cardboard are undistorted as regards their shape. There are deficiencies in the manufacture of corrugated cardboard, which impairs the quality of corrugated cardboard. Therefore, the need exists to further develop the manufacture of corrugated cardboard.